Hot air furnace



Nov. 20, 1962 R. c. JAYE ETAL 3,06439 HOT AIR FURNACE Filed May 31, 19605 Sheets-Sheet l I I ---J Nov. 20, 1962 R. c. JAYE ETAL HOT AIR FURNACE5 Sheets-Sheet 2 Filed May 31, 1960 F wm) Z .LEM m4 M- MMM 1 Nov. 20,1962 R. C, JAYE ETAL 3,064,639

HOT AIR FURNACE Filed May 31, 1960 5 Sheets-Sheet 3 4 l a? MM Nov. 20,1962 R. c. JAYE ETAL 3,064639 HOT AIR FURNACE Filed May 31, 1960 5shee'zs-sheet 4 5/ IE/ 53 721515570' L". Jay;

Nov. 20, 1962 R. c. JAYE ETAL I 3,064,639

HOT AIR FURNACE 5 Sheets-Sheet 5 Filed May 51, 1960 United States PatentO 3,064,639 HOT AIR FURNACE Richard C. Jaye and John F. Hirtz,Watertown, Wis., as-

signors to Syncromatic Corporation, Watertown, Wis., a corporation ofWisconsin Filed May 31, 1960, Ser. No. 32,798 13 Claims. (Cl. 126-116)This invention relates to furnaces and has more particularly referenceto gas-fired hot air furnaces for residential use.

In general, it is an object of the invention to provide a hot airfurnace with components that are designed to greatly facilitatemanufacture and assembly of the furnace at very low cost, and whichfeatures a heating unit that assures the transfer of heat to air fiowingthereover lfar more etficiently than is the case with conventionalheating units, though requiring considerably less metal for any givenBtu. output.

More specifically, it is an object of the invention to provide a hot airfurnace ofthe character described with an improved heat exchanger unitfeaturing primary and secondary heat radiating and transfer meansthrough which combustion gases fiow before discharging to a ilue, and

wherein novel :battle means incorporated in said heat radiating andtransfer means assures substantially uniform flow of combustion gasesover 'all the interior surfaces of said secondary heat radiating andtransfer means and the most efiicient transfer of heat thereby to aircirculated over its exterior surfaces.

With these and other objects in view, which will appear as thedescription proceeds, this invention resides in the novel construction,combination and arrangement of parts substantially as hereinafterdescribed and more particularly defined by the appended claims, it beingunderstood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawings illustrate one complete example of thephysical embodiment of the invention constructed according to the bestmode so far devised for the practical application of the principlesthereof, and in which:

FIGURE 1 is a side elevation of a gas-fired furnace embodying thisinvention, with wall portions of its casing broken away to show interiordetails of construction;

FIGURE 2 is a front elevational view of the .furnace with its frontcovers removed land with portions thereof broken away to illustratedetails of construction; o

'FIGURE 3 is a cross sectional view taken through FIG- URE 2 on theplane of the line 3-3.

FIGURE 4 is a perspective view of the heat exchange unit incorporated inthe furnace, viewing the same from the rear;

FGURE 5 is a fragmentary sectional view taken through FIGURE 2 on theplane of the line 5-5.

FIGURE 6 is van enlarged fragmentary sectional view taken through FIGURE1 on the plane of the line 6-6; and

FIGURE 7 is a fragmentary perspective view illustrating the manner inwhich the back draft deflector is mounted on the furnace casing.

Referring now more particularly to the accompanying drawings, in whichlike reference characters have been applied to like parts throughout theseveral views, the nurneral 10 generally designates the upright casingof a gasfired hot air furnace. The casing has rectangular verticallyelongated opposite side walls 12 joined at the rear of the furnace =by aback wall 13. Short inturned fianges 14 extend along the upright frontedges of the side walls, and these flanges terminate in short rearwardlydirected legs 15 which are parallel to the side walls. The space betweenthe legs 15 provides a wide opening in the -front of the 3,064,639Patented Nov. 20, 1962 casing, which is partially closed conjointly bythree cover sections located one above the other. These cover sectionscomprise an upper section 16, a lower section 17, and a foraminousintermediate cover section 18 in the form of an expanded metal grille.

In the furnace illustrated, a horizontal shelf 19 is fixed in the casingat an intermediate level, to divide its interior into a blowercompartment 20 in the space benea-th the shelf, and a heatingcompartment 21 in the space above the shelf. A 'blower 22 is mounted inthe blower compartment 20 in a manner to 'be described later, to forceair to be heated upwardly into 'the heating compartment 21 through ahole, not shown, in the shelf.

It should be understood, however, that this invention does not dependupon any particular location of the blower compartment. ciate that theblower compartment may =be above the heating compartment, or even to oneside of it if lowt height of the furnace is an important consideration.

As stated, the space inside the casing above the shelf 19 provides theheating compartment 21, which as is customary open-s through the top ofthe casing for connection with a heat delivery duct, not shown. Theheatingcompartment, of course, is defined in part by the side. walls 12and the back wall 13 of the casing. 'Ihe front` of the heatingcompartment is defined by an upright panel or face plate 24, whichextends transversely across the inside of the casing a short distanceinwardly from the` front thereof. The panel 24 -has a short rearwardlydirected flange 25 at its -bottom resting upon the shelf 19,-' and itsupper end terminates adj'acent to the top of thecasing. It also hasshort rearwardly directed fianges 26 extending along its opposite sideedges, and the panel constitutes the widest par-t of a su-bassembledheating unit generally designated 27.

'Ihe heating unit is designed and proportioned to enable the entireunit, including the panel or face plate 24, to be `assembled into thecasing through ythe front thereof. For

that purpose, the transverse dimension between the legs 15 on the side'wall fianges 14 is slightly larger than the distance between the sidefianges 25 on the face plate of the heating unit, to enable it to beeasily passed therebetween.

One of the features of the furnace of this invention i resides inthe'simplicity and ease with which the facef plate of the heating unitmay be secured in position withi in the casing 10. As stated previously,its bottorn fiange 25 rests upon the shelf 19, and it is held firmly inposition upon the shelf by its engagement under lthe free for-- wardlyprog'ecting endv portion of a spring finger 28 which has its base'29seating fiatwise upon the shelf behind the: flange 25 and securedthereto as by spot welding or the like. `The spring finger clamp 28-29which firrnly holds the fiange 25 down against the shelf may extendentireiI across the interior of the casing, or it may comprise aplurality of shorter, transversely spaced fingers if desired.

Also forming part of the means by which the face plate is secured inposition within the casing are a pair of rails, 5 generally designated3h. These rails have attaching legs 31 which flatwise overlie and arepermanently secured to the opposite side walls 12 of the casing, withthe rails extending vertically therealong ahead of the face plate 24.The rails are also provided with inwardly directed flanges 32 againstwhich the face plate fiatwise abuts, and narrow Persons skilled in theart will apple-- plate 'and the inwardly directed flanges 32 of therails can be alforded by adhering gummed tape around the rearwardlydirected face plate 'fianges and snugly wedging the taped fianges intheir channels 33.

Only four sheet metal screws are required to securely fasteh the faceplate in position Within -the front po'rtion of the casing. An upperpair of screws 35 pass through the opposite side portions of the faceplate at a location a distance downwardly from its top, and thread intothe fianges 32 on the rails 3th A lower pair of screws 36 likewise passthrough opposite side edge portions of the face plate and thread intothe flanges 32 on the rail's at a location near the bottom of the faceplate.

The heatiug unit 2 includes a heat exchanger 38 fabricated from Sheetmetal, and the design thereof constitutes one of the most importantfeatures of this invention. The heat exchanger, of course, is located inthe heating compartment 21 and it is secured to the back of the faceplate in a manner to be described shortly. It comprises a verticallyelongated main heating section 4G and a pair of upright but smallerheating sectionsror radiators '41 disp'osed 'at opposite sides of theupper portion of the main heating section. As seen best in FIGURE 1, themain heating section has a more or less rectangular Shape when viewedfrom the side, with its height substantially twice its fore and aftdimension.

V'Ifhe bottom portion of the main heating section provides ahorizontaliy elongated combustion chamber 42 extending from the rear ofthe face plate 24 to nearly the back wall 13 of the casing. The mainheating sectiori also includes an upper chamber 43 extending lengthwiseabove the combustion chamber at the top 'of the hea'ting compartment,and a duet-like intermediate 'portion '44 extending between and joinedto the upper and lower chambers 43 and w42, respectively, to rigidlyconnf'ect the same together with their interiors in communication withone another. A substantially large diameter cylindrical collar 45protruding from the front of the combustion chamber into a hole 46 inthe lower central portion of the face plate, and welded in place in saidhole, provides both an air inlet for the combustion cham- 'her as wellas an access port through which a gas burner 47 may be projected intothe interior of the combustion chamber.

The 'bottom portion of the combustion chamber has a semi-"cylindricalconfiguration coaxial with the collar 45 'and of the same diameter. Itmerges with oppos'ite side wall portions 48 which extend tangentiallyupwardly from the. combustion chamber only a short distance above thelevel of the top of the collar. Thus, the combustion chamber 'may besaid to be open at its top all along the fore and aft dimension of thechamber. The upper edges of the side walls 48 of the combustion chamberjoin edge- Wise with the lower ends of flat side walls `49 on theupright duet 44, |but it will be noted that the walls 49 converge towardthe upper chamber 43 and connect with the bottom of the latter through ashort lduct section 50. The upper duct section 54) has parallel uprightside Walls 51 Vjoined in an opening 52 in the upper 'chamber thatextends along the entire bottom thereof.

With this arrangem'ent, it will be seen that hot gases resulting fromthe com'bustion of g'aseous fuel in the combustion chamber riseupwardly'in the duct 44 to flow into the bottom of the upper chamber 43,but itwill be observed that the upper chamber is widened and hasopposite vertically extending side walls 53 which are parallel to thesides 48 of the combustion chamber and to the side walls .i 12 of thecasing, and which are offset outwardly from the opposite sides of theupper duct section 50.

Th Walls of the upper chamber 43, of course, provide secondary heatradiating and transfer surfaces, while those of the combustion chamberand the duct 44 aiford primary heat radiating andrtransfer surfaces.

VTheupper chamber 43 extends for and aft within the upper portion of theheating compartment, and it has a substantially rectangular crosssection, With somewhat greater height than width. Transversely opposedoutlet collars 55 fixed in suitable openings in the medial portions ofits side walls 53 and projecting outwardly therefrom provide ports toenable hot combustion gases entering the bottom of the upper chamber 43to exit therefrom after first being circulated around the interior ofthe latter, in intimate contact with the walls thereof. For this latterpurpose a bafile structure generally designated 57 isfixed inside theupper chamber. It comprises an elongated flat strip 58 of metal havingits lower end portion projectiug into and welded in place within the topof the upper duct portion 50, and its upper end abutting and welded tothe top of the upper chamber 43. Its flat sides are disposed normal tothe side Walls 53 of the upper chamber, but its opposite side edges 59are spaced a distance therefrom, as seen best in FIGURE 6.

'It will be noted that the strip 58 is located in a Vertical plane whichcontains the common axis of the outlet collars 55 of the upper chamber,and that a pair of oppositely curved defiectors '69 is secured to theopposite faces of the strip at locations within the upper end of theupper duet section 50, and the upper portions of the deflectors divergein Vfore and aft directions and extend into the Wider bottom portion ofthe upper chamber; Because of their Shape and location, therefore, thedeflectors more or less direct 'equal quantities of the hot icombustiongases entering the upper chamber 43 forwardly and rearwardly along thelower portion thereof and cooperate with the divider strip 53, to assurethat the gases will sweep across all of the, interior vsurfaces of theupper chamber, both lforwardly p and rearwardly of the divider, beforethey converge on the i. divi'der and vdis'charg'e in oppo'site lateraldirections from the outlets 55 of the chamber.

The 'combustion gases leaving the Vupper chamber 43 flow into theauxiliary heating Sections or radiators 41'at oppos'ite sides of theupper chamber 43, where more heat is abstracted therefrorri. Theauxiliary radiators are identical except that they are of right and leftconstruction. They extend vertically fo're and aft in the heatingcompa`rtment and are vsubstantially shallow or narrow in theirdimensions which are transversely of the casing. I

When viewed from the side, as seen in FIGURE 1', V'the hollow auxiliary'radiators 41 have a substantially 'rectangular'shape, with their foreand aft dimension substantially equal to that of'the duct '44 and thecombustion chamber therebeneath, and a Vertical dimension which issubstantially greater than that of the upper 'chamber 43 and nearlone-half the total height of the main heating section 40. At its sidefacng the adjacent upperv chamber 43, each ofthe auxiliar' radiators isprovided with an inlet opening 62 in which the Vou'tlet collars 55 onthe `upper chamber are fi`xed 'so that the radiator vis rigidly joinedto'the upper chamber by said collars.VV

The inlets 62 of the auxiliary radators are located in the upper centralportions of their inner sides, so that a substantial port-ion of eachradiator extends both fore andV aft as well as downwardly from theinlet, Short Outlet Vcollars 63 -at the upper front corners of theauxiliary radiators provide discharge ports through which 'combustiongases exit there'from, vand the collars project forwardly into and a-rewelded within similarly shaped holes iu' the front panel 24 to enablecombustion gases to be disclha'rged into a zone in the upper frontporton of the casmg, ahead of the vface plate 24. t

VSince the discharge ports provided by the Outlet collars 63 areubstantially close to the inlets 62 thereof and 'substantially'at thesame level, means must be provided' to prevent combustion gasesenterngthe auxiliary radiators from discharging directly to, their outletports, without first contacting all of the wall surfaces of theradiators to enable the extraction of all of the heat possible from thegases. Novel baflle means, generally desgnated 65, .is provided for thispurpose, one such baflie means being located inside of each of theradators.

The bafi'le means 65 in each auxiliary radiator 41 comprises adismountable upper bafile section 66 and a fiXed lower section 67. Thebaffie section 66 comprises a substantially elongated rectangularplate-like strip of metal supported in the upper front portion of theauxiliary radiator and dismountable through the outlet collar 63thereof. It edgewise bridges the narrow dimension of the radiator andextends downwardly from its top at a location intermediate the inlet 62and outlet 63 thereof. The upper portion of the strip extends forwardlythrough the outlet collar 63, at the top thereof, and has a tab 68 bentupwardly therefrom to lie flatwise against the front of the face plate.This tab extends upwardly into a narrow downwardly opening channel 69formed integrally with the top of the face plate and extendingtransversely thereacross, to releasably hold the upper front portion ofthe bafile section 66 in position within the radiator. Preferably, thebafile section 66 extends downwardly and rearwardly away from the outletcollar to a level at least even with the lower edge of the inlet 62 ofthe radiator.

If desired, of course, the baffie section 66 could be disposed more orless vertically within the auxiliary radiator, although its positionintermediate the inlet and out-` let openings of the radiator isessential since it then may be relied upon to block direct passage ofincorning gases to the Outlet collar 63.

lower portion of the auxiliary radiator, beneath the inlet' It ispermanently secured in a laterally tilted 62 thereof. position withinthe radiator, as by rack welding, with its lower edge near the bottom ofthe radiator and in continuous contact with inner side wall (having theinlet 62). The upper edge of the body plate is in continuous engagementwith the outer side wall of the radiator and at about the same level asthe bottom of the inlet 62.

The forward end of the plate 71 is Vertical and disposed a distancerearwardly from the front of the radiator but ahead of the inlet 62. andsubstantially in line with the lower end of the inclined upper bafllesection 66. Its rear edge however is disposed adjacent to the rear ofthe radiator, but it is slanted downwardly and forwardly toward thebottom of the plate, as indicated at 72.

The body plate 71, therefore serves to divide a substantial part of thelower portion of the auxiliary radiator into a pair of laterallyadjacent compartments, namely, an inner compartment 73 and an outercompartment 74, with the compartments located at opposite sides of theplate. The two compartrnents are communicated with one another aroundthe tapered rear edge 72 of the plate, but they are closed off from oneanother at the front of the plate by a flange or partition 76 on thefront end of the plate, extending laterally inwardly therefrom andabutting the inner side wall of the radiator.

To facilitate its attachment, the flange 76 may be provided with anattaching lip 77 bent forwardly therefrom and fiatwise secured to theinner side wall of the radiator, as by tack welding, to close the frontof the inner compartment 73.

The flange 76 is spaced a substantial distance from the front of theauxiliary radiator, and its upper edge serves as a seat upon which thelower end of the inclined upper bafile section 66 is readily detachablysupported so as to form, in effect, a continuation of the flange 76.

Due to the cooperation between the upper and lower bafile Sections, andbecause communication between the rear of the outer compartment and theinlet portions of the radiator is substantially restricted, combustiongases entering the upper or inlet portion of the radiator cannot flowfreely into the outer compartment 74 and are thus caused to spread outinto and sweep across all areas of the upper portion of the radiator asweil as of the inner compartrnent 73, to eifectively heat those portionsThe side edges of the bafie section 66, of course, are contiguous to theopposite side wallsv 6 thereof which are in heat transfer relation toair to be heated.

Since combustion gases entering the radiator must fiow through the outercompartment 74 in order to reach the outlet of the radiator, such gasesare thus constrained to flow downwardly and rearwardly around thetapered rear edge 72 on the lower baffie section, then forwardly throughthe outer compartment 74 into the space ahead of the flange 76 on thelower bafiie section, from whence they may travel upwardly to anddischarge from the outlet collar 63.

The particular disposition of the bafiie means in each auxiliaryradiator, as described above, assures intimate contact between thecombustion gases entering the radiator and substantially all of thewalls of the radiator before such gases are discharged therefrorn. Thisachieves very efiicient heat transfer between such gases and aircirculatcd over the exterior of the radiator, with a minimum of Sheetmetal employed in the radia-tors.

It is important to note that with the baffle construction described,combustion gases flow faster through the smaller outer compartment 74than through the larger inlet section of the radiator, to thuscompensate as much as possible for the diiferences in area between theirrespective heat. transfer surfaces and materially contribute towarduni-.

form heating of all portions of the radiator.

Also, since the effective cross sectional area of the outer compartment74 decreases progressively from the bottomof the radiator toward the topof the body plate 7d, com-= bustion gases would ordinarily flow throughthe narrow upper portions of the outer compartment, without coming intothe transfer relationship with the walls thereof' The downwardly andfor-- Wardly tapering rear edge 72 on the body plate of the lower battlesection, however, efiects proper distribution` at its wider lowerportion.

and control of the flow of combustion gases through the outercompartment 74 by reason of the fact that it progressively restricts theentrance to the outer compartment toward the narrower upper portionsthereof, causing pro- 'outer compartment of the radiator, to assureuniform heating of the adjacent outer Wall of the radiator to nearly thesame degree as the walls of the radiator which define the inlet portionsthereof.

As stated previously, the upper edge of the partition or flange 76 onthe front end of the lower bafiie section provides a seat upon which thelower end of the upper' or inclined bafiie section 66 is readilydetachably supported. In order to removably hold the lower end of theupper bafr'ie section against accidental displacement, a'

tab 78 is struck forwardly from its lower end to engage in front of theupper edge portion of the flange 76, while legs 79 at either side of thetab engage the upper rear of the flange.

Attention is directed to the fact that the main heatingl section 46 aswell as each of the auxiliary radiators 41 are formed from only two moreor less shallowl but mating pan-like sheet metal section fixed togetherby a welded seam 81 that extends continuously about their mating edges.Their design, moreover, is such as to permit their being die-drawn andsecured together by a minimum of welding, as distinguished from moreconventonal constructions involving press braking or rolling, or the useof a multiplicity of die-drawn Sections.

Not only does this design of the various sections of the heat exchangerenable their manufacture at low cost, but

it allows modular assembly thereof into various combinations of main andauxiliary Sections in order to vary the' B.t.u. output of the furnace.By way of example, in a furnace designed for a relatively low B.t.u.output, only a main heating section 46 would suffice, and the auxiliaryopposite notches 95 on the side wall fianges.

aoeaeee i 7 radiators would be omitted. In that case, of course, theupper chamber 43 would be formed With imperforate opposite side walls,and a discharge port or outlet collar (not'shown), similar to the collar63 on Veach auxiliary radiator, Would be fixed in its front end.

As another example, two such main heating sections 40 could be fixed inVside by side relationship to the back of the face plate 24 of the heatexchanger unit, with a gas burner for each of the combustion charnbersof the section. Each of the upper chambers 43 would have a suitabledischarge port provided in its front, and the upper chambers would alsobe communicated with one another as by a collar 55 such as employed toconnect the upper Chamber with each auxiliary radiator in the embodimentdisclosed in the drawings.

In a reduced output furnace, it might suifice to provide only oneauxiliary radiator,41, While in a furnace having two main heatingSections 40, as many as three auxiliary radiators could be used toadvantage for most efiicient heat radiation and transfer to aircirculated over the exterior surfaces of the heat exchanger.

In addition to being supported by the front panel 24, the main heatingsection in additionally supported at its rfear upon the shelf 19, as bymeans of a short length of angle iron 83 welded to the underside of thecombustion chamber and having a horizontal flange to seat flatwise uponthe shelf. A strap 84 also extends across the rear of the heatexchanger, adjcent to the bottorn of the auxilia'rytradiators, and iswelded to both ofthe latter and t'o the rear of the duet section 44 tolend rigidity to the Unit.

The combustion gases which discharge from the auXil-I iary radiators 41are received in a boxlike collector 86 attached to the upper frontportion of the face plate 24, over 'the combustion gas outlet portstherein. The entire 'bottom of the collector is open, but it has a frontwall 87 parallel to the face plate or panel 24 and substantially flushwith the front edges of the casing, and opposite side walls 88 bentrearwardly from the side margin of the front wall but diverging towardthe panel 24. The rear e'dges of the side walls are turned inwardly, asat 89, to

provide vertically extending flanges that seat fiatwise upon theopposite marginal portions of the panel. A horizontal wall 90 closes thetop of the collector, and a short upstanding flue collar 91 is securedin the top wall to adapt the collector for attachment to a fiue.

The collector is secured in 'position on the upper front portion of thefront panel 24 in an exceedingly simple manner. For this purpose, anupstanding ange 93 is formed along the rear of the collector top wall,coplanar with Vthe side flanges 89. This fiange projects upwardly intoand fits within the narrow 'transverse channel 69 on the top of the faceplate, tobe more or less snugly confin'ed 'therein together with the tab68 on the upper b'afile section 66.

The lower portion of lthe collector is secured to the front panel V24 ofthe heating unit by means of the upper pair of sh'eet metal screws 35,which also pass through the side fianges 89 of the collector near itsbottom, and thread into the rails behind the panel 24. lt is a featureof this invention that the collector side `fianges S9 cooperate withtransversely opposite downwardly and forwardly angl'ed notches 95 in the'legs 15 of the side wall fianges 1'4 to provide a simple and readilydetachable mounting for a diverter baflle' 96 in a position vbeneath theopen bottom of the collector. The dverter baffle extends downwardly vandforwardly from the bottoms of the collector flanges, and its purpose isto divert air forwardiy out of the casing away from the discharge portsof the auxiliary radiators, in case of sudden back drafts.

The baffie or diverter 96 is supported in the desired inclined positionbeneath the open bottom of the collector by having lits lower edgereceived in the transversely Its upper end rests against the face plate.and an upstanding fiange `98 on the upper end of the baffie is clampedbetween the vingly shaped opening, not shown, in the shelf.

end portions of the collector flanges are separated from the collectorside walls by slits 99, and the diverter flange 98 fits only behind thefree end portions of the collector flanges, beneath the screws 35.

At its lower end, an intermediate portion of the divert:- er .baflle isbent therefrom to form a narrow upwardly opening channel 101 to receivea downwardly directed lip 102 on the upper end of the grille 18, so asto suitablyisuspend the grille therefrom. Since the lip 102 .on' thegrille extends transversely between the legs 15 on the side wallflanges, the upper end of the grille is held against all but Verticaldetaching motion by its connection With the lower end of the diverter.

The lower end of the grille `also vhas a downwardly directed lip 103 atits rear which hooks over an upstanding flange 104 on the front end ofthe shelf 19, to thus cooperate with the diverter engaginglip 102 inreadily removably holding the .grille in position upon' the casing.

To detach the grille 18, it is only necessary to grasp 1 it at itsopposite side edges and lift it upwardly ashort distance to disengageits upper and lower lips fromithe casing carried parts that normallyhold the grille in place on the casing.

The lower cover 17 also has a 'hook 106 that engages over the upstandingfiange 104 on the-shelf 19, beneath the lip 103 on the grille, to bethereby detachably suspended from the front of the casing.

As is customary, fuel supplied to the gas burner 47 passes through amain control valve 108 which acts to close off the floW of gas to themain burner in the event of failure of a pilot burner 109 for the mainburner. i The pilot burner 109 may be mounted directly on the side ofthe main burner, as shown. i

The main burner is supported conjointly by the face plate 24 and thebottom of-the combustion chamber, as shown, and it includes an elongatedmixing tube 110 which projects forwardly through the front ofthecombustion Chamber and the face plate 24, as seenv best in FlGURE 1.The front endV of the mixing tube is Vfiared Voutwardly and forwardly soas to be substantially bell or trumpet shaped, and at its forwardextremity it has a stationary air shutter disc 113.

As is customary, the shutter disc 113 has butterfly openngs 116 atdiametrically opposite sides of the hole.

These butterfiy openings cooperate with similar butterfly openings in arotatable air shutter disc 117 flatwise contiguous to the rear face ofthe stationary disc.

A nipple 123 having one end threaded into the outer end of a fitting 122that is connected to the front of the mixing tube and having its otherend threaded into the outlet of the main valve 108, serves to mount themain Valve on the front of the burner mixing tube 110 in a stablefashion. With the construction described, the entire gas burner and themain valve constitute an assembly which can be installed in thefurnaceas a subassembled unit to save considerable time and expense in themanufacture of the furnace.

The blower 22 is secured to the underside of the shelf 19 with theduct-like discharge mouth 125 of the blower projecting upwardly and inregister with a correspond- The mounting means for the blower includes apair of elongated cleats 127 welded to the underside of the shelf, andextending fore and aft adjacent to opposite sides of the opening in theshelf. Each cleat has a downwardly stepped or otfset portion whichprovides a Vertical leg 128 and a horizontal ledge 129 extendinginwardly from the bottom of the leg. The ledges 129 are coplanarspo-goes 9 and spaced equal distances below the shelf 19, and theycooperate with their respective legs 128 to atford drawerlike guideswhich slidingly receive cooperating protuberances 130 on the oppositesides of the blower discharge duct to enable the blower to be slid toand from its operative position seen in FIGURE 1 much in the manner of adrawer, thus facilitating the installation on and removal of the blowerfrom the shelf.

The cleats 127 are preferably spot welded or otherwise permanentlyafiixed to the underside of the shelf 19, and in Cooperation with theunderside of the shelf, their legs 128 and ledges 129 form Channelswhich open toward one another.

According to this invention, the protuberances 130 on the opposite sidesof the blower discharge duct are resilient, being provided bycylindrical rubber cushions or pads suitably mounted on the oppositeside walls of the discharge duct as by means of studs, not shown. Also,their diameter is such as to enable them to be snugly but slida'olyreceived in the space between the underside of the shelf and thehorizontal flanges of the Channels provided by the ledges 129.

A felt sealing strip 134 or a similar sealing device is preferablyclamped against the underside of the shelf by each cleat 127, as by anolfset intermediate retaining portion 133, and the inner edges of thestrips abut the opposite sides of the blower discharge duct.

With the construction described, the blower can be slid into the blowercompartment from the front of the furnace vmuch in the manner of adrawer. It will be understood, of course, that the guides or Channels inwhich the cushioning pads 130 are received are open at their forwardends at the time of assembly of the blower into the casing. The ledgesmay be bent upwardly, as at 135, at their rear ends to provide stopswith which the rubber cushioning pads engage to define the rearmostposition of the blower within its compartment. After the blower is inposition in the blower compartment, however, the forwardly projectingfront portions of the ledges 129 may be bent upwardly ahead of theforemost cushions, as at 136, to prevent forward motion of the blowerrelative to the casing.

This manner of mounting the blower in the furnace casing is not onlysimple and inexpensive, but it achieves a cushioned Suspension of theblower by which vibration thereof during its operation is dampened inall directions to preclude transmission of such vibration to the casingwalls.

Air to be heated may he introduced into the blower compartment througheither side wall 12, or through the back wall 13 of the compartrnent. Ineither event, a con- Ventional filter 137 is interposed between the airinlet opening in the blower compartment and the inlet of the blower.

From the foregoing description taken together with the accompanyingdrawings, it will be apparent to those skilled in the art that thisinvention provides a hot air furnace which features a heat exchangerwhich, because of its high efiiciency, may be fabricated fromconsiderably less sheet metal for a given B.t.u. output than waspossible' heretofore; and wherein unique lmeans for mounting thecollector, the diverter and the blower on the furnace casing results inreduced manufacturing and assembly costs.

What we claim as our invention is:

l. In a hot air furnace: a casing including upright opposite side wallsconnected by an upright back wall; an upright face plate extendingacross the interior of the casing a distance rearwardly of the front ofthe casing, and connected to the side walls so as to cooperate with themand the back wall in defining a heating compartment in the spaceenclosed thereby, said face plate extending to the top of the casing andhaving means on its upper end providing a substantially narrow channelthat extends transversely across the top of the casing and opensdownwardly directly ahead of the plane of the face plate, and said faceplate having a flue gas discharge port in an upper portion thereof; aheat exchanger in said compartment including a combustion chamber inwhich fiuid fuel may be burned, and fiue gas discharge meanscommunicating with said port to conduct Combustion gases out of the heatexchanger and into a zone ahead of the face plate; a back draftdeflector extending across the interior of the casing ahead of the faceplate and beneath said zone; means on the front portions of the sidewalls engaging the lower edge portions of the draft deflector forsupporting the same from the casing in an upwardly and rearwardlyinclined position with its upper edge adjacent to the face plate and ata level beneath the fiue gas discharge port therein; a fiue gascollector in the upper front portion of the casing, ahead of the faceplate and above said deflector, said collector defining a chamberencompassing the zone into which combustion gases flow from said ue gasdischarge port, being open at its bottom, having a top wall providedwith an opening through which flue gases leave the chamber, and havingopposite side fianges that overlie the front of the face plate atlocations at opposite sides of the fiue gas discharge port therein;means securing the collector to the face plate comprising an upstandingflange on the top wall of the collector at the rear thereof, confined insaid narrow channel on the upper end of the face plate, and fasteningdevices, one at each side of the collector near the bottom thereof,securing the collector flanges to the face plate; and interengagingmeans on the collector and the deflector holding the upper portion ofthe latter against movement away from the face plate.

2. The hot air furnace of claim 1, wherein said interengaging means onthe collector and deflector comprises a flange on the upper portion ofthe deflector confined between the lower end portions of the collectorside flanges and the front of the face plate and clampingly heldtherebetween by said fastening devices.

3. The hot air furnace of claim 2, wherein said fastening devices arescrews that pass through portions of the collector side flanges whichare located above the defiector fiange, and wherein the collector haslower portions of its side flanges separated from the adjacent walls ofthe deflector by slits to enable the collector flanges to be pulledtight against the front of the face plate at areas above the deflectorflange by said screws.`

4. The hot air furnace of claim 1 further characterized by the provisionof: a baffle in the heat exchanger' having an upper portion whichextends forwardly through the top of said flue gas discharge port; andmeans detachably mounting said bafile in the heat exchanger comprisingan upwardly directed tab on the upper end of said baffle, overlying thefront of the face plate and engaged in said substantially narrow channelon its upper edge so as to be confined in said channel together with theflange on the top wall of the collector.

5. The hot air furnace of claim 1, wherein said face plate has anopening in its lower portion through which air necessary to supportcombustion enters the combustion chamber; a grille covering a frontportion of the casing ahead of the face plate and extending transverselyacross the casing, and through which air enters the front portion of thecasing for flow into the combustion chamber; and means mounting saidgrille on the front of the casing, comprising a lip on the lower end ofthe deflector defining a substantially narrow upwardly opening groovethat eXtends transversely across the lower end of the deflector, and adownwardly directed flange on the upper end of the grille releasablyhooked into said groove.

6. In a hot air furnace: a casing including upright opposite side wallsconnected by an upright back wall, and inwardly directed flanges on theupright front edges of the side walls; an upright face plate extendingacross an upper portion of the interior of the casing in spaced relationto the side Wall flanges and vcooperating with the back and side wallsto define a heating compartrnent in the casing, said face plate havingan air inletlopening in a lower central portion thereof and having -afiue gas displate, said heat exchanger including a combustion chamber-which is supplied with air necessary to support combustion-throughsaidair inlet opening in the lower portion of the face plate, and said heatexchanger including forwardly extending flue gas discharge meanscommunicating With said port in the upper portion of the face plate todischarge combustion gases into a zone in the front of the casing aheadof the face plate; a back draft deflector extending across 'the casingahead of the face plate and beneath said zone; means on the fiangedfront edge portions of the side walls engaging the lower edge portion ofsaid draft deflector for supporting the same from the casing in anupwardly andV rearwardly inclined positionrwith its upper edge adjacentto the face plateand at a level beneath the flue gas discharge porttherein; a flue gas collector in the upper front portion of the casingahead of the face plate and over said deflector, said collector defininga Chamber encompassing the zone into which combustion gases flow fromsaid flue gas discharge port, being open at its bottom, having a vtopwall provided with an'opening through which flue gases leave thechamber, and having opposite side flanges that extend vertically alongthe front of the face plate at locationsat opposite sides of the fluegas V discharge port therein; means secun'ng `the face plate in positionwithin the front portion of the casing comprising rails behind the faceplate, fixed to the opposite side walls of the casing and Vhaving narrowvertically extending forwardly openingichannels therein, rearwardlyprojecting flange means on the opposite upright edges of the face platesnugly lreceived in said channels in the rails, an upper pair offastening devices, one at each side of the collector near the ibottomthereof, engaging said rails and extending through the collector flangesand the face plate to secure the same to said rails, and a lower pair offastening devices each engaging the face plate and one of said rails todraw the same into firm lengagement with one another; and interengagingmeans 'on the collectorand the deflector holding the upper portion ofthe latteragainst movement away from the face plate, whereby said upperand lower pairs of fastening devices serve to hold the face plate, thecollector and the deflector in position on the furnace casing.

7. The hot air furnace lof claim 6, whereinthe heat exchanger is fixedto the rear of the face plate and forms therewith a subassembled unitthat receives support from the lcasing side walls through said pairs of.fasteningdevlces.

-8.' A'heating unit for 'hot vair -furnaces, comprising: an upright faceplate-having a central hole in a lower portion thereof and having a fluegas discharge port in -an upper portion thereof; la heat exchangermounted on the back of the face plate, for transferring heat toairflowing thereover, said heat exchanger having primary heat radiatingand transfer surfaces, comprising a lower'chamber extending horizontallyrearwardly from the lower portion of the face plate and having anopening in itsfront-registering with the central hole in the face plate,through which fuel and air may be introduced into the chamberfor'combustion therein, said lower chamber being open along its top toenable combustion gases to rise therefrom, `and upright ductrmeansconnected with` said lower chamber along its top for conductingcombustion gases upwardly therefrom, said heat exchanger havingsecondary heat transfer surfaces comprising an upper chamber behind theupper v'portion of the face plate, said upper chamber having an inletopening in an upper central portion of one side thereof by which it isconnected with said duct, means to receive combustion gases therefrom,and 'being subits top,,for conducting combustion gases upwardly there-`12 stantially narrow but having opposite sides which Vextend substantialdistances fore and aft as well' as downwardly from the level of saidinlet opening, and having a flue gas outlet in its upper front portionconnecting With the flue gas discharge port in the face plate; andbafile means in said upper chamber comprising an upper transverse bafilemember extending downwardlyV from the top of said upper chamber at leastto the level of the lower edge of the inlet opening thereof and inspaced relation to the front of the chamber butintermediate its inletand outlet' so as to prevent incoming combustion gases from travelingforwardly to said outlet thereof, a substantially upright bafile memberin the lower portion of said upper chamber, beneath its inlet andextending rearwardly from the lower portion of said upper bafile membertoward the rear Vof the upper chamber but having a lower rear portionthereof spaced from the rear of the chamber, said lower 'bafifle membercooperating with side wall portions of t'ne chamber at opposite sidesthereof to define laterally adjacent compartments in the interior of theupper chamber, one of which compartments opens directly into the inletspace in the upper portion of the chamber rearwardly of said Vupperbafile member and the ,other of which compartments communicates withsaid inlet space only around the lower rear portion of said lower bafliemember, and an uprighttransversely extending wall member closing thefront of said one compartment and serving substantially as a downwardextension of said upper baffle member so as to cooperate with the latterand with the lower 'baffle member in constraining combustion gasesentering the inlet space of the upper chamber to travel to the outletthereof via a circuitous route leading downwardly and rearwardly throughsaidvone compartment, around the rear of said lower baflle member,forwardly through said other compartment, and then upwardly ahead ofsaid Wall member and the upper 'baifle member toward the Outlet of saidupper chamber.

9. The heating unit of claim 8, wherein said lower bafile member is asubstantially flat plate which occupies a tilted position in the upperchamber, with its bottom adjacent to the side of the chamber having theinlet, and its top adjacent to the opposite side of the chamber.

lOThe heating unit of claim 9, wherein said Vplate has a rear edgetwhichtapers downwardly and forwardly away from the rear of the' upper chamberso as to restrict the flow of combustion gases into the narrow Vupperportions of said other compartment.

11.V The' heating unit of claim 8, wherein said upright Wall member isformed integrally with said plate and is bent to `one side thereofat thefront of the plate.

A'12. The heating unit of claim 11, wherein said upper 'bafile member isremovable from the upperfchamber.

through said outlet and the flue gas discharge port, and has an upperend portion which projects forwardly through vthe top of said outlet andthe'flue gas discharge port and is detachably connected .to the faceplate at the front side thereof, andwherein said upper 'baffle has abottom portion which is 'detachably seated upon the upper edge of'saiduprightwall member.

13. .A heating unit for hot air furnaces, comprising: an uprightfaceplate having a central hole in a lower portion thereof and having a fluegas discharge port in an upper portion thereof; a heat exchanger mountedon the back of the face plate and comprising a combustion chamberextending horizontally rearwardly from the lower portion of the faceplate and having an opening in its front registering with the centralVhole in the face plate, through which fuel and air may be introducedinto the chamber for combustion therein, said chamber being open alongits top to enable combustion gases to rise therefrom; upright duct means'connected with the combustion chamber along from; a ,first hollowradiator fixed to the upper end of the duct means and into the 'bottomof which the duct means opens to discharge combustion gases thereinto,said first 13 radiator extending lengthwise over the combustion chamberand having an outlet in one side thereof through which combustion gasesdischarge; a second hollow radiator laterally adjacent to said firstradiator and extending both downwardly and in fore and aft directionswith respect to the outlet of said first radiator, the side of saidsecond radiator which is adjacent to the first radiator having an inletopening which registers transversely With the outlet of said firstradiator, and said second radiator having a flue gas discharge port inits upper front portion; a duct connecting the outlet of the firstradiator With the inlet of the second radiator and rigidly joining saidradiators together; and bale means in said second radiator comprising atransverse partition member extending downwardly from the top of theradiator at least to the level of the lower edge of the inlet and inspaced relation to the front of the radiator but intermediate the fluegas discharge port and the inlet, to prevent incoming combustion gasesfrom traveling forwardly toward the discharge port, a substantiallyupright partition member in the lower portion of the radiator, beneaththe inlet, and extending rearwardly from said partition member towardthe rear of the radiator but having a lower rear portion thereof spacedfrom the rear of the radiator, said substantially upright partitionmember cooperating With walls of the radiator at opposite sides thereofto define laterally adjacent compartments one of which opens directlyinto the inlet space in the upper portion of the radiator rearwardly ofsaid first named partition member and the other of which compartmentscommunicates with said inlet space only around the lower rear portion ofsaid second designated partition member, and an upright transverselyextending wall member closing the front of said one compartment andserving substantially as a downward extension of said first designatedpartition member to cooperate with the latter and with the seconddesignated partition member in causing travel of combustion gasesentering the inlet space of the radiator to the discharge port via acircuitous route leading downwardly and rearwardly through said onecompartment, around the rear of said second designated partition member,forwardly through said other compartment, and then upwardly ahead ofsaid wall member and the first designated partition member to the fluegas discharge port.

References Cited in the file of this patent UNITED STAT ES PATENTS Jayeet al. Oct. 1,

